From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Thu, 25 Jun 2026 19:33:58 +0000 (+0200)
Subject: 7zip: Check skip in setup_decode_folder
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e9e9b2ebccafd6d44500a6d71ea0eb4bb9ecd09e;p=thirdparty%2Flibarchive.git

7zip: Check skip in setup_decode_folder

Make sure that all bytes are actually skipped. Normally, the result can
be ignored because the bytes were read previously. Here, more bytes than
previously read will be skipped.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
---

diff --git a/libarchive/archive_read_support_format_7zip.c b/libarchive/archive_read_support_format_7zip.c
index 202c1d8c4..e4f528d86 100644
--- a/libarchive/archive_read_support_format_7zip.c
+++ b/libarchive/archive_read_support_format_7zip.c
@@ -468,7 +468,7 @@ static int	read_SubStreamsInfo(struct archive_read *,
 		    struct _7z_substream_info *, struct _7z_folder *, size_t);
 static int	read_Times(struct archive_read *, struct _7z_header_info *,
 		    int);
-static void	read_consume(struct archive_read *);
+static int	read_consume(struct archive_read *);
 static ssize_t	read_stream(struct archive_read *, const void **, size_t,
 		    size_t);
 static int	seek_pack(struct archive_read *);
@@ -1249,16 +1249,23 @@ archive_read_format_7zip_cleanup(struct archive_read *a)
 	return (ARCHIVE_OK);
 }
 
-static void
+static int
 read_consume(struct archive_read *a)
 {
 	struct _7zip *zip = (struct _7zip *)a->format->data;
 
 	if (zip->pack_stream_bytes_unconsumed) {
-		__archive_read_consume(a, zip->pack_stream_bytes_unconsumed);
+		int64_t r;
+
+		if ((r = __archive_read_consume(a,
+		    zip->pack_stream_bytes_unconsumed)) < 0)
+			return ((int)r);
+
 		zip->stream_offset += zip->pack_stream_bytes_unconsumed;
 		zip->pack_stream_bytes_unconsumed = 0;
 	}
+
+	return (ARCHIVE_OK);
 }
 
 #ifdef HAVE_LZMA_H
@@ -3990,7 +3997,8 @@ setup_decode_folder(struct archive_read *a, struct _7z_folder *folder,
 			return (r);
 		zip->pack_stream_bytes_unconsumed =
 		    zip->pack_stream_inbytes_remaining;
-		read_consume(a);
+		if ((r = read_consume(a)) < 0)
+			return (r);
 
 		/* Read following three sub streams. */
 		for (i = 0; i < 3; i++) {